A Nagios alternative that still runs your plugins.
Looking for a Nagios alternative? Nagios Core is free and endlessly extensible with plugins, and Nagios XI adds a commercial interface priced per node, but flow analysis and log collection are separate Nagios products with their own licences. TarleyNode puts network monitoring, flow analysis, syslog, SNMP traps and maps in one self-hosted install, and it is compatible with Nagios plugins.
TarleyNode and Nagios side by side
| Feature | TarleyNode | Nagios |
|---|---|---|
| Where it runs | Your own Linux server | Your own 64-bit Linux server [1] |
| Agentless | Yes: SNMP, WinRM, SSH and APIs | Yes, agents optional [1] |
| NetFlow, sFlow, IPFIX | Included | Separate product: Network Analyzer [3] |
| Syslog and SNMP traps | Included | Traps in XI; syslog in Log Server [1] [4] |
| Windows servers | WinRM: health, services, counters | NCPA, NSClient++, WMI or WinRM [1] |
| VMware and Hyper-V | Yes | Yes, through premium wizards [6] |
| Azure and AWS | Yes | Yes, plus Google Cloud [1] |
| Remote sites | Connected sites, included | Distributed monitoring [1] |
| LLDP and CDP map | Yes | Partly: status map by parent, NagVis [1] |
| High availability | Option, USD 480 a year for 3 servers, with an alert when no server is active | Partly: documented options, a licence per system [1] [8] |
| Single sign-on | OpenID Connect or Microsoft | AD, LDAP or Microsoft Entra ID [1] |
| Nagios plugins | Compatible | Native [2] |
| Phone apps | No, browser console | Mobile web interface [7] |
| Free use | 30-day trial, then free to 100 sensors | Core free; XI free for 7 nodes [1] |
Numbers in brackets link to the Nagios page each answer comes from.
Prices
| Product | Listed price | Covers |
|---|---|---|
| Nagios Core | Free | Open source under GPL v2 |
| Nagios XI Standard, 100 nodes | $2,595 | Perpetual licence, first year of support included |
| Nagios XI Standard, 500 nodes | $8,295 | Perpetual licence, first year of support included |
| Nagios XI Enterprise, 100 nodes | $4,690 | Adds capacity planning and SLA reports |
| Nagios Network Analyzer | $4,995 | Flow analysis, on its own server |
| Nagios Log Server, 1 instance | $5,195 | Syslog and log management |
Nagios lists these as one-time perpetual licences, with the first year of maintenance and support included. Nagios defines a node as anything with an IP address or fully qualified domain name.
TarleyNode is free for up to 100 sensors after a 30-day trial, then from USD 600 a year for 500 sensors, about 50 devices, with flow analysis and syslog included.
Where Nagios is stronger
- Nagios Core is free and open source under GPL v2.
- Thousands of community plugins, and any executable that returns an exit code can become a check.
- Perpetual licences: Nagios XI Standard keeps running whether or not maintenance and support is renewed.
- Four ways to monitor Windows: NCPA, NSClient++, WMI or WinRM.
- Google Cloud and Akamai Cloud monitoring alongside AWS and Azure.
- Capacity planning and SLA reports in the Enterprise edition.
Where TarleyNode differs
- NetFlow, IPFIX and sFlow traffic summaries, syslog and SNMP traps are all part of one product, with no separate servers or licences.
- An LLDP and CDP network map, a switch port mapper and configuration backups over SSH with change history.
- A high availability option with standby servers, a witness and automatic failover, for USD 480 a year covering three servers.
- Discovery scans and device templates that add a standard set of checks and alert rules in one step.
- Public status pages and a NOC wall display.
- Single sign-on with OpenID Connect or Microsoft, and two-step sign-in, built in. In Nagios XI, single sign-on is a premium feature tied to active support.
- Compatible with Nagios plugins, so familiar checks still have a place.
Which team should pick which
Pick Nagios if you already have a large investment in Nagios configuration and plugins, want free open-source Core, or prefer a perpetual licence.
Pick TarleyNode if you want network monitoring, flow analysis, syslog, maps and configuration backups from one installer and one licence, while keeping the Nagios plugins you rely on.
Switching from Nagios
- Install TarleyNode on a separate server or virtual machine.
- Run a discovery scan of the networks Nagios monitors, using the same SNMP and Windows credentials.
- Apply device templates, then compare alerts and reports from both over a few weeks.
- Switch when you are satisfied, and keep Nagios running until you no longer need it.
Questions
Can TarleyNode run my Nagios plugins?
Yes. TarleyNode is compatible with Nagios plugins, alongside its own SNMP, WinRM, SSH and API checks and custom sensors for REST APIs and scripts.
Is Nagios free?
Nagios Core is free under GPL v2. Nagios XI has a free licence for 7 nodes or 100 services, whichever is reached first, and paid licences start at $2,595 for 100 nodes.
Does Nagios XI include NetFlow and syslog?
Nagios XI polls SNMP and receives traps. Flow analysis is Nagios Network Analyzer and log collection is Nagios Log Server, each a separate product with its own licence. TarleyNode includes NetFlow, IPFIX, sFlow, syslog and SNMP traps.
Does TarleyNode have high availability?
Yes, as an option. It adds standby servers and a witness for automatic failover and rolling updates, for USD 480 a year covering three servers.
Does TarleyNode run on Linux like Nagios?
Yes. The current TarleyNode release installs on Ubuntu or Debian, x86-64, with a single installer.
See TarleyNode on your own network
Ask for an invitation through Request a demo; every request is read by a person. An evaluation includes every feature with unlimited sensors for 30 days, and TarleyNode then stays free for up to 100 sensors. It does not change device configuration, so it can run next to Nagios while you compare.
Guides
Other comparisons
Sources
- Nagios XI
- Nagios Core
- Nagios Network Analyzer
- Nagios Log Server
- Nagios pricing plans
- Nagios XI premium features
- Nagios XI mobile interface
- Nagios XI high availability options
Nagios details were checked on the vendor’s own website in October 2026. TarleyNode details describe release 0.3.6. If anything here is out of date, tell us at sales@tarleynode.com. Product names are trademarks of their respective owners. TarleyNode is not affiliated with or endorsed by them.